The importance of antigens in the prevention of infectious disease through immunization is well known. The basis of immunization is the exposure of the animal to be immunized to dead or weakened infectious agents (viruses, bacteria, toxins, etc.) or extracts thereof which contain a foreign, generally macromolecular substance which is capable of evoking an immune response. These substances are generally referred to as antigens.
Most antigens are either wholly or partially composed of protein. The action of antigens is thought to be dependent in part on the antigen's affinity for certain binding sites on cells of the immune system. These cells may be present in blood and internal organs. Interaction of the antigens with the binding site stimulates the immune system which, when actuated, defends the organism against infectious agents.
Antigens can have adverse side effects on the organism sought to be immunized. This is important in the treatment of humans and animals. It is therefore desirable to be able to achieve an effective immunogenic response while utilizing lower levels of an immunogenic antigen. If immunogenicity of an antigen can be increased, a smaller dosage of the antigen can be administered to achieve a given level of immunity.
One way to increase immunogenicity of a substance is by using an adjuvant in conjunction with the substance. An adjuvant is a substance which augments the immune response. Adjuvants can have toxic and other side effects. Thus, adjuvants are generally disfavored for use in humans or in any other organism where toxicity and/or side effects are a concern. The elimination of the need for adjuvant utilization by otherwise increasing immunogenicity of the antigen is therefore desirable.
Some substances do not evoke an immune response at all, or do so very poorly, when brought into contact with cells of the immune system. It would be advantageous to be able to convert such substances from a non-immunogenic form to an immunogenic form. This would allow vaccines to be produced where this was not previously possible.
Immunization is normally carried out by subcutaneous or intramuscular injection of the vaccine. Oral administration of an antigen is not feasible in most instances because it often causes suppression rather than an increase of the immune response. Exceptions to this general rule include live attenuated bacterial and viral vaccines. Oral vaccines offer advantages such as lower expense and ease in administration and packaging. Therefore, it would be advantageous to be able to administer non-live vaccines in oral form.
The catonization of protein-containing substances has been known for some time (see reference 15 below). Several methods of cationizing proteins have been described to modify the protein so as to produce animal models of arthritis and glomerulonephritis. However, none of the prior art has disclosed, suggested or demonstrated enhanced immunogenicity of cationized protein-containing substances.
There has heretofore been no recognition in the prior art that partially cationized antigens can be used in in vivo treatment and prevention of disease. Furthermore, the prior art has not recognized that partially cationized antigens can be used as vaccines. Indeed, it has been reported that cationized proteins do not exhibit enhanced immunogenicity (see reference 9 below).
An aspect of the present invention relates to the discovery that partially cationized antigenic protein-containing substances possess enhanced immunogenic properties. Through this discovery, a method of enhancing immune response to a native antigen is provided.
Other background information is contained in the following references which are hereby incorporated by reference:
1. Barnes, J. and M. Venkatachalam, Enhancement of Glomerular Immune Complex Deposition by a Circulating Polycation. J. Exp. Med. 160:286 (1984).
2. Olte, S. P. Batstord, J. J. Mihatson, H. Takamija and A. Vogt, Quantitative Studies on in situ Immune Complex Glomerulonephritis in the Rat Induced by Planted Cationized Antigen. J. Exp. Med. 155:460-474 (1982).
3. Gallo, G., Caulen, T. Glaser, S. N. Emancipator and M. E. Lamm, Nephritogenicity and Differential Distribution of Glomerular Immune Complexes Related to Immunogen Charge. Lab. Invest. 48:460 (1983).
4. Schikwik, J., W. B. Van den Berg, L. B. A. van de Putte, L. A. B. Joosten & L. van den Bersselaar, Cationization or Catalase, Peroxidase, and Superoxide Dismutase: Effect or Improved Interarticular Retention on Experimental Arthritis in Mice. J. Clin. Invest. 76:195 (1985).
5. Muckerheide, A. J. Pesce and J. G. Michael, Immunosuppressive Properties of a Peptic Fragment of BSA. J.Immunol. 119:1340 (1977).
6. Dosa, S., A. J. Pesce, D. J. Ford, A. Muckerheide and J. G. Michael, Immunological Properties as Peptic Fragments of Bovine Serum Albumin. Immunol. 38:509 (1979).
7. Muckerheide, A., A. J. Pesce and J. G. Michael, Kinetics of Immunosupporession Induced by Peptic Fragments of Bovine Serum Albumin. Cell. Immunol. 50:340 (1980).
8. Muckerheide, A., A. J. Pesce and J. G. Michael, Modulation of the IgE Immune Response to BSA by Fragments of the Antigen. Cell. Immunol. 59:392 (1981).
9. Border, W. A., H. J. Ward, E. S. Hamil and A. H. Cohen, Induction of Membranous Nephropathy in Rabbits by Administration of an Exogenous Cationic Antigen. J. Clin. Invest. 69:451 (1982).
10. Apple, R., B. Knauper, A. J. Pesce and J. G. Michael, Shared Determinants of Native and Denatured Bovine Serum Albumin are Recognized by Both B- and T- Cells. Mol. Immunol. 21:901 (1984).
11. Levine, B. B. and N. M. Vaz, Effect of Combinations of Inbred Strain Antigen and Antigen Dose on Immune Responsiveness and Reagin Production in the Mouse. Int. Aron. Allergy Appl. Immunol. 39:156 (1970).
12. Ferguson, T. A., T. Peters, Jr., R. Reed, A. J. Pesce and J. G. Michael, Immunoregulatory Properties of Antigenic Fragments from Bovine Serum Albumin. Cell. Immunol. 73:1 (1983).
13. Julius, M. H., E. Simpson and L. A. Herzenberg, A Rapid Method for the Isolation or Functional Thymus-derived Murine Lymohocytes. Eur. J. Immunol. 3:645 (1973).
Hoare, D. G. and D. E. Koshland, A Method for the Quantitative Modification and Estimation of Carboxylic Acid Groups in Proteins. J. Biol. Chem. 242:2447 (1967).
15. Danon, D. L. Goldstein, Y. Markovsky and E. Skutelsky, Use of Cationized Ferritin as a Label or Negative Charges on Cell Surfaces. J. Ultrastructure Res. 38:500 (1972).
16. Warren, H. S., F. R. Vogel and L. A. Chedid, Current Status of Immunological Adjuvants. Ann. Rev. Immunol. 4:369 (1986).
17. Mills, Z. J. and E. Haber, The Effect on Antigenic Specificity of Changes in the Molecular Structure of Ribonuclease. J. Immunol. 91:536 (1963).
18. Heber-Katz, E., D. Hansburn and R. H. Schwartz, The Ia-molecule or the Antigen-presenting Cell Plays a Critical Role in Immune Responses Gene Regulation of T Cell Activation. J. Mol. Cell. Immunol. 1:3 (1983).
19. Buus, S., and 0. Werdelin, Oligopeptide Antigens of the Angiotensin Lineage Compete for Presentation by Paraformaldehyde-treated Accessory Cell to T Cells. J. Immunol. 136:459 (1986).
20. Babbit, B. P., P. M. Allen, G. Matsueda, E. Haber and E. R. Unanue, Binding of Immunogenic Peptides to Ia Histocompatibility Molecules. Nature (London) 317:359 (1985).
21. Buus, S., S. Color, C. Smith, J. H. Freed, C. Miles and H. M. Grey, Interaction Between a "Processed" Ovalbumin Peptide and Ia Molecules. P.N.A.S. 83:2968 (1986).
22. Larey, E. X., E. Margoliash, F. W. Fitch and S. K. Pierce, Role of L3T4 and Ia in the Heterocolitic Response of T Cells to Cytochrome. J. Immunol. 186:3933 (1986).
23. A. N. Glazer, R. J. DeLange and D. S. Sigman, Chemical Modifications of Proteins. Lab. Techniques in Biochemistry and Mol. Biology, Vol. 4, Part I, p. 1-205. North-Holland (Am. Elsevier) (1976).
24. Alexander N. Glazer, The Chemical Modification of Proteins by Group-Specific and Site Specific Reagents. 1-103. In: The Proteins. 3rd ed. Vol. II Acad. Press, N.Y. (1976).
25. A. J. Pesce, R. Apple, N. Sawtell, and J. G. Michael, Cationic Antigens, Problems Associated With Measurement by ELISA. J. Immunol, Meth. 87:21 (1986).
26. Unanue, C. R. and J. C. Cerottini, Antigen Presentation, The FASEB Journal, 3:2496 (1989).
Where cited herein, these publications are referred to by their numbers in the above list.